Thrymjótur

Thrymjótur or more commonly Thrymjir is the magical, dwarven-forged hammer wielded by the thanir god Kórd. Described as a super weapon, it is an immensely strong and hefty item that is able to channel the Thunderlord's powers with such ferocity, that even the god of strength himself needs to wear a pair of magical gauntlets, the Yerbrahni, to wield it for long periods of time.

Background
When the many enemies of Voðir grew numerous, he ventured to Angramar, and to the home of Ánvildi who was a blacksmith famed in all the realms. The Raven King had come to commission a weapon for his son Kórd, one that was mighty and that his recklessness might never lose him. When Ánvilldi refused, his two sons, eager to make a name for themselves, answered the Raven King's request.

And so the brothers set to work, and crafted a weapon with no equal. From the depths of Rekvenyr, they heaved iron imbued by dragon's tears. From the World Tree, they sawed a single branch. And from the sea, they stole an echo of its thunderous might.

With this feat of craftsmanship, they became even more famous than their father, who passed away of illness some years later.